Retrieves all factors from a given level of the hierarchical structure that include the specified combination of blocks.
get_level_factors(factor_list, combination, level)A matrix of concatenated factors matching the given level and combination, or NULL if no match is found.
A named list of factors for each node (from build_factor_structure).
Integer vector. Indices of the blocks involved in the current node.
Integer. The hierarchical level (i.e., the number of blocks involved).