1. A non-transitory computer-readable medium storing program instructions executable by a processor of a computing system to: receive instruction from a user to create a user-customized virtual association between a first user-selected element and a second user-selected element of one or more business object models of a UI component model; determine a node of a first business object model of the virtual association; determine a second business object model node of the virtual association; define foreign key parameters in the UI component model describing a foreign key relationship associating a user-selected attribute of the first business object model node with a user-selected attribute of an element of the second business object model node, wherein the foreign key relationship defines the virtual association; propagate the virtual association to a service layer configured to evaluate the foreign key relationship and provide corresponding data of the associated elements; and create metadata in the UI component model associating the element of the UI component model with the second attribute of the element of the second business object model, the metadata comprising the foreign key parameters.