This is a complaint about this feature I mentioned here. You can in theory make this work by checking the “Auto Approve Enabled” box at the bottom of the setup page under “SailPoint IdentityNow for Service Catalog → Setup”
Note that in your case here, it will escalate the approval to the next manager up. Meaning if Person A is the manager of Person B and requests access for Person B, the manager approval step will escalate to Person A’s manager, Person C. EDIT: this is incorrect, see my corrected post below.
Again, I don’t like how this works because I feel like it’s trying to solve an issue that doesn’t exist.