Power Query - Need HLP

Hello,

i m looking for solution for Power Query:

1. Lookup Value - Same Table or Different Table

I have a formaula, but i get information back,  - Circle reference
Idea behind this is DAX = LOOKUPVALUE('Sales Account'[ID2],'Sales Account'[accountid],'Sales Account'[id])
____

(let

searchValue = [id]

in

Table.SelectRows(

    #"Sales Account",

    [accountid]=searchValue)

){0}[ID2]

2. Countif (without merging Tables)?

var sItem= Table1[Item]

var sVisit= Table1[Visit]

CALCULATE(COUNT(Table1[Item]),FILTER(Table1,Table1[Item.]=sItem),FILTER(Table1,Table1[Visit]=sVisit))

3. IF MAXX?

var sItem= Table1[Item]

var sVisit= Table1[Visit]
var sCreated = Table1[Created at]

IF(MAXX(FILTER(Table1,Table1[Visit]=sVisit&& Table1[Item]=sItem),Table1[Created at)=sCreated ,1,0)