RANKX depending on filter context

Here's what I ended up doing. amitchandak TOPN was the soultion after all, thanks.

SalesVolume:=var Top5 =

TOPN(5,SUMMARIZE(

ALLSELECTED(Producers),

Producers[HoldingCo],

"TopSalesAmt",

[SalesAmt]

),[TopSalesAmt])

var Subtotals = NOT(HASONEVALUE(Producers[HoldingCo])

var TopRank = IF(HASONEVALUE('Top'[Group]) && VALUES('Top'[Group])="Top 5",1,0)

var Top5Sum= SUMX(Top5,[SalesAmt])

var Top5Total = IF(NOT(HASONEVALUE(Producers[HoldingCo])) && HASONEVALUE('Top'[Group]) && TopRank = 1,TRUE(),FALSE())

var OtherTotal = IF(NOT(HASONEVALUE(Producers[HoldingCo])) && HASONEVALUE('Top'[Group]) && TopRank = 0,TRUE(),FALSE())

return

IF(NOT(HASONEVALUE('Top'[Group])),[SalesAmt],

IF(Subtotals=TRUE(),

IF(TopRank=0,CALCULATE([SalesAmt],ALL('Top'[Group]))-Top5Sum,Top5Sum),

IF(Subtotals=FALSE(),

IF(TopRank=0,IF(NOT(CONTAINS(Top5,Producers[HoldingCo],VALUES(Producers[HoldingCo]))),[SalesAmt],BLANK()),

IF(CONTAINS(Top5,Producers[HoldingCo],VALUES(Producers[HoldingCo])),[SalesAmt],BLANK())))))