1. A computer-implemented method for expanding search results, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: identifying, within results of a search, a document that is a member of a document family that includes at least one other document; determining that a user has made a selection to include, within the results of the search, the document family; creating a data map that includes a representation of the document identified within the results of the search at least in part by identifying a unique identifier associated with the document that corresponds to an offset within the data map and representing the document by toggling a bit at the corresponding offset on the data map; based on the determination that the user made the selection, expanding the data map by including, within the data map, a representation of each of the at least one other document in the document family; using the expanded data map to include the document family within the results of the search.