You will only be able to view plans within Collaborator if the plan has been shared with you by your trading partner. You may not be able to see a plan if it has not reached your stage in the approval process and therefore, you will not be able to view or sign off the deal yet.
Please contact your trading partner to ensure this is the case.
If no plans have currently been sent for signing/viewing - the following screen will be shown in Collaborator:
If there are plans for viewing and signing, the following screen will be shown listing all current plans for that partner: