Hi,
There are two parts to this :-
1. Make an object's modeler as shareable
You can try making one Object's Modeler as Shareable(check-box) by going to the 'Information Tab' of Object's Properties.
You can access Object's Properties by Clicking on Edit Menu of the Object -> Properties Option.
2. Enable other objects to access application model of the parent object.
Once, you have selected which Object's Modeler you want to share, next part is to enable other objects to access this shared modeler.
You can do this by selecting the Option - ""Share the application model of another object"" option on the Application Modeler Wizard.
Once you select this option, it will show you all the objects who have shared their modeler.
Here, select the object whose application modeler you want to access as parent object here.
Hope it helps!