Navigating Excel via Row for value change respectively as per category

I have data in sheet 'DATA' with this values :

Then I have the 'navigator' sheet called 'NAV' with this structure :

In 'NAV' G9 cell, I have this formula :

     =INDEX(COLUMN(DATA!$H$4:$N$566)-7,
AGGREGATE(15,6,COLUMN(DATA!$H$4:$N$4)-COLUMN(DATA!$H$4)+1/
(DATA!$H$3:$N$3=G$7),ROWS(G$9:G9)))

The issue is, I try to drag down from G9:G17 (remarks : it will be more than that), but the value didnt change accordingly as per 'DATA' sheet. The value taken also wrong. If I put value 'PER' in 'NAV' G7, cell G9:G7 will change to ''AAA', 'BBB, 'CCC' and so on respectively. Those values will change when I put 'T1', 'T2', and so on based on 'DATA' legend.

Can you guys please help? Already change here and there and it's not working.

Thanks!

Try something along the lines, you need the COUNTIF() function for the headers i.e. PER, T1, T2 etc :

=IFERROR(INDEX(DATA!$H$4:$N$13,
 AGGREGATE(15,7,(ROW(DATA!$G$4:$G$13)-ROW(DATA!$G$4)+1)/
 ($F9=DATA!$G$4:$G$13),COUNTIF(G$7:G7,G7)),
 MATCH(G$7,DATA!$H$3:$N$3,0)),"")

Or, simply can use INDEX()+MATCH()+MATCH()

=IFERROR(INDEX(DATA!$H$4:$N$13,
 MATCH(DATA!$G4,NAV!$F$9:$F$16,0),
 MATCH(G$7,DATA!$H$3:$N$3,0)),"")

In MS365 it would be using FILTER() & XLOOKUP()

=XLOOKUP(F9:F16,DATA!G4:G13,FILTER(DATA!H4:N13,(G7=DATA!H3:N3)),"")