See Dealing Clips and Interleaving Clips.
The Deal node deals out the frames of a single clip evenly to any number of destination clips. The Clip field defines the number of times the clip is split; the Frame determines which of the dealt clips is output.This node supports floating-point (OpenEXR) clip input.
The First Processed Frame field sets the value at which output is processed from the node. Unprocessed output does not display any media.