Selecting Distinct ID in multiple selection sets and count total

[ensoliman20]

i want to find of count of people who completed both visit 17 and 23 together the distinct so total if 17 and 23 selected is 2 

ID Visit

1 17

1 23

2 17

3 17

2 23 

[PriyankaShivhare]

sum(if(aggr(count(Distinct Visit),ID)=2,1) )

Hope This Helps!

Thanks,

Priyanka