Search/Filter works nicely, but it searches within the same Entity (speaking about CDS). Recalling Access Web Apps I used to create a form (gallery in PowerApps) that its datasource is a query coming from 2 or more entities, then i can search/filter any column in the query (in any table that joined the query).
I wish that Search/Filter functionality in PowerApps is extended so I can search/filter a gallery from colums not eactly existing in the gallery datasource but from a related entity. For instance, I have an Entity of ACCOUNTENTITY, and each account exist in a COUNTRY from COUNTRYENTITY, imagine the gallery from ACCOUNTENTITY, searching to COUNTRY will not work because Search work only for those fields in the entity itself.
Thanks @Yahya - we are looking to introduce support for views within Canvas apps, which would allow you to do the type of filtering and searching you mention. Please let me know if you have any additional feedback.