Commonly used scheduling algorithms in high-level synthesis only accept one process at a time and are not capable of sharing resources across process boundaries. This results in the usage of at least one resource per operation type and process. A new method is proposed in order to overcome these restrictions and to share high-cost or limited resources within a process group. This allows the use of less than one resource per operation type and process, while keeping the mutual independence of the involved processes. The method represents an extension of general scheduling algorithms and is not tied to a specific algorithm. It is applied to the time constrained Force-Directed Scheduling algorithm. For this the scope of the scheduling is extended to the processes of the whole system and a two-part modification is applied to the original procedure. A multi-process example illustrates the resource sharing capabilities of the extension.