Well we can only work with information given...
Add a helper column in the My Selections sheet, say column Q, and assuming row 1 is headers.
In Q2 and filled down put
=SUBTOTAL(103,G2)
Then use that column in your countifs / Averagifs formulas
=COUNTIFS('MY SELECTIONS'!G:G,"1ST",'MY SELECTIONS'!Q:Q,1)
=AVERAGEIF('MY SELECTIONS'!Q:Q,1,'MY SELECTIONS'!O:O)
=AVERAGEIFS('MY SELECTIONS'!O:O,'MY SELECTIONS'!G:G,"1ST",'MY SELECTIONS'!Q:Q,1)