Hi Lucas,
From your pictures I believe it is but just want to confirm - are the entitlements you are trying to bundle into one provisioning plan of the same entitlement type?
Also after some more digging, I believe these entitlements would need to be a part of the same role or access profile to be grouped together. Found this solution on the forums by Colin that describes this behavior - Get multiple entitlements in access request within the same plan - #2 by colin_mckibben
Found some other solutions where people have called back to the ISC APIs in a before rule to see what other access was requested by the user and then add those to the prov plan. This solution is much more involved though. Will link it here for your reference - Combine multiple entitlement types into one provisioning request
Thanks!
Liam