Limiting data in one list (chart) based on values in a second

[#1]

I have two groups of students and their sporting interests. 

If I select a value from School A, I serve up their interests.   In this case, Bob is interested in 4 sports.     Bob matches to many students on anywhere from 1 to 4 sports.

In School B, it turns out that Bob has 6 matches from the other school (they match on one of Bob's sports) and their sports interests include 10 sports. 

Q:  How can I limit the rows in the second object based on matching to to A_Sport?     This way, I can ask Bob what sports he's REALLY interested in and serve up the corresponding matching students  

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ps:

I am keeping the variable names as A_Sport and B_Sport to prevent loops in the data model 

  I've tried =if(match and other expresions and am having no luck

Right now I can sort Bob's sports to the top of the second list but I'm also including ALL the other sports from students at School B

Chart In Qlikview:

A_ID, A_Sport

Bob,Football

Bob,Basketball

Bob,Tennis

Bob,Cricket

Chart or List in Qlikview:

B_ID,B_Sport

Sally, Swimming

Tony, Tennis

Tony,Cricket

Alex,Bowling

Alex,Football

Alex,Chess

Alex,Racing

Alex,Shotput

Mary, Badminton

Mary,Basketball

Mary, Tennis

Mary,Swimming

Jet,lawn bowls

Jet,Bowling

Jet,Cricket

[Anonymous]

If I got your request right - simply rename A_Sport and B_Sport to the same name, e.g. Sport.  The rest QV will do for you.

[#3]

Hi

I understand that. Challenge I’m getting is a circular loop in loading my model .

I’ve been trying expressions such as =if(match, A_Sport, B_Sport) and using it as a conditional view in presentation.

[Anonymous]

Can you upload a sample of your application?  Otherwise its impossible to guess...