What do you mean when you say you don't have workflow access yet? You need to build the workflow for approval. You cannot achieve this with a form alone

I have built a separate workflow within the sharepoint calendar. All I am trying to achieve in the form is to make the approve/deny radio buttons only accessible by the manager of that group.

Check what current user returns and compare it with the string 'Manager Name'. It could be that the strings do not match. Current User is probably returning a value of format: i:0#.w|domainusername.

I tried using that that format too. How would I write out it out. Maybe I am doing that piece incorrectly.

Does the Manager Name change or its a hard coded value that is always the same?

If it doesn't change you can try extracting the current user's username, then comparing it with the Manager's username. So basically you do the following;

1. Create a form variable (name: CurrentUserUsername) of type string and formula: userProfileLookup(Current User,"Username")
2. Create a formatting rule on the control that you want to hide: CurrentUserUsername != 'ManagerUsername'

This works, but there's probably an easier and shorter way of achieving this result.

I will give it a shot. Thanks for the suggestions.