Hiding Report Duplicates Iif

[father]

How can I hide in a report duplicates conditional on whether another field [ConduitNumber] is hidden?

Query results:

ConduitNumber Size CableNumber
1234C 3/4 CableA
1234C 3/4 CableB
2345C 3/4 CableC

after using conditional hide command in Report:

ConduitNumber Size CableNumber
1234C 3/4 CableA
CableB
2345C 3/4 CableC

In a normal Hide the 3rd 3/4 Size would also not show up.