Page Automatically Filling in Data Based on Adjacent Cells mentions Edit - Fill - Series that is now in the Sheets menu
Adolfo Jayme Barrientos committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/help/commit/?id=4b1bb982611b888fa7c4b11c614ea32c54f980a2 tdf#97588 Update menu path for Series