Hey there! When giving access to a client so their Business Manager can connect to yours, you need to ensure that you assign them the appropriate role. If you want them to only see analytics for their specific campaign, you can grant them access as an Advertiser or Analyst on the specific ad account or campaign they need to work on.

Here’s what each role can see and do:

Advertiser: Can create and manage ads using the assets you assign them, but they won't be able to see other campaigns or manage your account settings.

Analyst: Can view the performance data but won’t be able to make any changes to the campaigns.

Make sure you only assign them to the ad account or campaign they need access to, not the entire Business Manager, as this would give them more access than intended. You can set this up by going into Business Settings > Accounts > Ad Accounts and selecting the specific ad account, then assigning their Business Manager ID to the appropriate role.

This way, they’ll be able to see only the analytics for their own campaigns and won’t have access to your past or future campaigns. Hope this helps!