ok, thanks!
but if I have this table:

STATION.........ID.....USE.......UL_ID.......AREA_POND
BA..............1......ALG.........41...........20,1
BA..............3......ALG.........41...........26
BA..............5......ALG.........42...........23
BA..............7......ALG.........42...........10,1
BA..............8......ALG.........42...........50
BA..............10.....ALG.........43...........49,31
BA..............11.....AE..........75...........10,1
BA..............13.....AE..........75...........300
BA..............15.....AE..........75...........300
BA..............16.....AE..........76...........50
..................................................
..................................................
RG..............1......ALG.........21...........12
RG..............3......ALG.........21...........15,2
RG..............5......ALG.........32...........22
RG..............7......ALG.........32...........13,1
RG..............8......ALG.........32...........50
RG..............10.....ALG.........33...........48,31
RG..............11.....AE..........65...........19,1
RG..............13.....AE..........65...........390
..................................................
..................................................
MI..............1......ALG.........11...........12
MI..............3......ALG.........11...........15,2
MI..............5......ALG.........12...........22
MI..............7......ALG.........12...........13,1
MI..............8......ALG.........12...........50
MI..............10.....ALG.........93...........48,31
MI..............11.....AE..........85...........19,1
MI..............13.....AE..........85...........390
..................................................
..................................................
..................................................
..................................................

Can I create just one view group by STATION?
or must I create one view for each STATION?

Thank you very much!
Rgds
Raf