If the 'Applied Profile' field is blank next to the cluster, then there are 2 ways to get this information: -
1. Directly edit the Transport Node profile and it will give the details on which cluster or hosts its applied. The other alternate is below.
2.Expand the NSXT prepared cluster, and edit an individual host, and click the 'Configure NSX' tab on the top and go through the wizard, and in the second page it should give the details of the transport node profile applied. Please make sure to cancel the wizard after getting this info. Hope this will be helpful.