Could you please share a bit more about your scenario?
Do you want to combine/join multiple data source within a PowerApps app, then display the combined result within it?
Further, could you please share a bit more about your data source?
On your side, if there are some unique join keys between your multiple entities, I think the AddColumns function could achieve your needs. The standard formula as below:
AddColumns(Table1, "Region", LookUp(Table2, Name = Table1[@Name], Region))
Note: The Name column represents the unique join key between Table1 and Table2.
More details about the AddColumns function, please check the following article: