Try to fetch data from table level
Pass functional location to TPLNR field in table IFLOT and fetch OBJNR field
then pass OBJNR field to table EQUI of field OBJNR and fetch whatever details you required from that table. From this table, you can get Equipment number, Material & Material part no.
If it doesn't show any data then confirm like there is no data for the functional location.
After all this you got data but no fulfilling your requirement with FM or BAPI then better go with custom BAPI.
Logic should be: Create BAPI with import parameter as functional location (TPLNR) and in tables parameter add structure (i.e. whatever fields your required as XML file). The flow should be as mentioned above
And move all the data into final internal table (i.e. Table Parameter).
Sample BAPI creation:
A step by step guide for beginners on user defined BAPI creation - ABAP Development - SCN Wiki
Regards,
Praveen Reddy