[SalesForce] Restrict Contacts only related to Account that is associated to a Custom Object

I tried to implement this, but could not able to find a straight solution.

You can try below solution.

1. Create a new Lookup field (Account) on Quote object.

2. Then apply a lookup filter criteria on Contact field as below,

3. Once you select a Account lookup, the contact field will display only those contacts which are related to selected Account.

4. The only overhead here is, user needs to select extra Account field and then user will select the associated Contact.

While there is no direct solution to my scenario, here is the workaround I used:

1. I added a lookup field for the mutual object (in this scenario, an Account lookup)

2. I created custom buttons to replace the standard 'New' button for the joint object's related lists that appear on both the contact and asset page layouts.

3. I used URL hacking on these buttons to prepopulate the account lookup with the Asset or Contact's account info.

That way the Account lookup is already populated when someone clicks 'new' from either the asset or contact pages. And since the account lookup is now present on the joint object, lookup filters using that account info can be applied to the related contact and asset lookups.