How to reference to previous matching record using arrayformula?
问题 I have a project spreadsheet, with project managers entering current progress status for each project for each month where there was some activity. So the columns A B and C are filled, I need to be able to figure out the column D using arrayformula. (note that there was no activity/record for "Project 1" in June 2019) I thought I would first need a helper column to find the date of the previous record for the project and then vlookup the date for the project and return the progress of that