RingCentral CIF for Dynamics 365 only searches the Regarding field using these endpoints:

/api/data/v9.0/accounts

/api/data/v9.0/contacts

/api/data/v9.0/leads

/api/data/v9.0/opportunities

/api/data/v9.0/incidents

That means searches are limited to just the name or title fields, which is pretty restrictive.

Request

Switch to using the Dynamics 365 Search API endpoints:

/api/search/v1.0/suggest

/api/search/v1.0/query

These endpoints allow searches across all fields that Dynamics administrators have marked as searchable, including any custom fields customers add.

Why this matters

Users can find records based on any searchable field, not just name/title.

A single API call can return Accounts, Leads, Contacts, Opportunities, and Incidents.

Custom fields are fully supported, so organizations with tailored Dynamics setups aren’t left out.

Search scope is still controlled by Dynamics admins, so governance and compliance are respected.

Overall, this makes the CIF much more useful and saves time for teams working in Dynamics every day.