Why I can't use hierarchy of some dimension in raws of data grids, and can use it in data forms?

HFM doesn't allow to use some dimension hierarchy in data grids and gives me a message "The current selection is invalid. List not allowed"? Why? Is any restriction for use dimension's hierarchy in data grids? And why system allows me to use it in data forms? Of course I can  build a temporary form to debug a problem but it is longer then make a temporary data grid.