[SalesForce] Related list button not displaying on opportunity record in Lightning Experience

Indeed, just redirecting to the record will not fire a refresh event. However, sforce.one.back takes a "refresh" parameter, so if you only need to go back to the record you were on (a "nav back") you can just use sforce.one.back(true).

There's an [example of this as a VF component][https://github.com/SalesforceFoundation/Cumulus/blob/dev/src/components/UTIL_NavigateBack.component] in the NPSP:

<apex:component >
    <apex:attribute name="recordId"
        description="The recordId to navigate to."
        type="Id"
        required="true"
        />
    <apex:attribute name="redirect"
        description="Prevent redirect unless set to true."
        type="Boolean"
        default="false"
        />

    <script type="text/javascript">
        var redirect = {!redirect};
        if (redirect) {
            if ((typeof sforce != 'undefined') && sforce && (!!sforce.one)) {
                // Manage navigation in Lightning Experience & Salesforce1
                    sforce.one.back(true);
            }
            else {
                var recordId = '{!recordId}';
                // Manage navigation in Salesforce Classic
                window.parent.location.href = '/' + recordId;
            }
        }
    </script>

</apex:component>

You will have to add custom Lightning Component. Lightning Experience provides ability to add custom built component.

• Create a custom component having a button which would perform same function as custom button used to perform.
• Go to Lightning builder, Click new
• Select Record Page then the Object on which it needs to be shown.
• Choose "Clone Default Saledforce Home page
• Add the component, and activate that new page.

Another way:

Add Action to the page. - Go to Object - Find Custom, Button and Links Section - Click "New Action" Add the Lightning component you want same as below