Learn English – Is the adjective phrase “hungry and tired” “attributive” in the sentence “After the long journey, the three of them went back home, hungry and tired”

The problem is that grammar is somewhat tied to meaning here. The position of an adjective in a sentence depends on its role.

When used attributively (to describe a noun), as stated in other comments and answers, the adjective comes before the noun:

All navigable rivers are being patrolled.

If you say:

All rivers that are navigable are being patrolled. (Others are not)

This can become:

All rivers navigable are being patrolled.

At first glance this doesn't really seem to change the meaning since:

rivers that are navigable = navigable rivers

Edit: But...

When an adjective comes after the noun it describes (like in the 3rd example), it functions as a postpositive modifier. Changing the position of the adjective (relative to the noun it describes) may bring a slight difference in the meaning of the sentence (the meaning of the word itself does not change!). When used postpositively an adjective connotes an ephemeral quality, one that is present at the moment, but doesn't always have to be. On the other hand, the adjectives used attributively may express either an ephemeral or a permanent characteristic, depending on the context. The difference between attributive and postpositive use of an adjective is explained in more detail in (the middle of) this post and in the comments.

Only some adjectives can be used both attributively and postpositively (while retaining the same word meaning), and these are the ones ending in -able and -ible (such as navigable). (But not even all of those - see later: responsible).

To cover another aspect (this is where grammar kicks in again): if an adjective is used predicatively (in a pattern: subject + verb + object + complement (here an adjective)) it would be in a sentence like this:

Signalisation on the banks made rivers navigable. (Or something like that, I'm not really an expert on rivers).

The upcoming event made people excited.

The meaning of some adjectives (when used as modifiers) changes depending on whether they are used attributively or postpositively. Some examples are: concerned, responsible, present etc. Neither navigable nor excited are among those. Here the meaning of the word itself changes and the difference can be determined by checking the dictionary definitions.

The difference between adjective complements and adjective phrases depends on the difference between the parts of a clause and the parts of speech. 

We use the phrase "parts of speech" to refer to the nature of words.  Parts of speech include things like nouns, prepositions, adverbs and adjectives.  We can apply the same labels to units that are larger than a single word -- meaning that noun phrases, prepositional phrases*, adverb phrases and adjective phrases are all labels that refer to collections of words that act as a single grammatical unit and that fulfill the same functions as the individual words.  An adjective phrase is a phrase that contains an adjective and that can do the same job as an adjective on its own. 

We use the phrase "parts of a clause" (or, more traditionally, "parts of a sentence") to refer to the ways that words and phrases relate to each other -- to the jobs that words and phrases have.  Parts of a clause include things like subjects, direct & indirect objects, and complements. 

An adjective complement is an adjective (or an adjective phrase) that fulfills the job of a complement. 

Consider the following: 

He is a very happy man. 
That man is very happy. 
His hobbies make him very happy. 

In every one of the sentences above, the phrase "very happy" is an adjective phrase.  The adverb "very" modifies the adjective "happy", and the two words together can do the same jobs that the adjective "happy" can do on its own. 

In the first sentence, "very happy" directly modifies the noun "man", and it is part of the noun phrase "a very happy man".  In turn, "a very happy man" is a part of the clause, specifically a predicate nominative subject complement. 

In the second sentence, "very happy" has a different job. Instead of being a part of a noun phrase, it is the part of the clause that we call a predicate adjective subject complement. 

In the third sentence, we can see another example of an adjective complement.  This time, "very happy" serves as a predicate adjective object complement. 
 

The label "adjective complement" applies to both predicate adjective subject complements and predicate adjective object complements.  It applies to both one-word adjectives and to adjective phrases -- no matter how long or involved the adjective phrase may be. 

When we talk about adjective phrases, we're talking about the nature of the phrase or the way the phrase is built.  When we talk about complements, we're talking about the way that something fits into its clause or the job that some word or phrase satisfies. 
 

When we talk about adjective complements, we're mentioning both the nature of the word or phrase and the kind of job it performs. 

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* Prepositional phrases are a special case.  Prepositional phrases consist of prepositions and their arguments.  Unless we expand this discussion to include intransitive prepositions, it doesn't make much sense to say that prepositional phrases do the same jobs as prepositions on their own.  For a similar reason, we can avoid the complexities and confusion of the label "verb phrase".