You can link a key date to a specific participant as well as a work type in sharedo modeller.

1. Launchpad > Modeller > Work type modeller, locate and select the work type to with which the key date is associated.
2. Left-hand navigation: Type Relationships > Key dates
   
3. Locate the key date you wish to link > click the burger menu > Edit > Scroll down to the Participant role aspect of the Edit Key Date Association blade.
   
4. Click on the Participant role drop-down field and select the role to which you want to link the key date.

You can now link a key date to a participant.