Find my approach as reference below and stored in attached workbook version 10.5 located in the original thread.
1. M1. Workdays: sum([Work Days])/count([Month])
2. M2. Window Sum Sales: window_sum(sum([Sales]))
3. M3. Window_sum Workdays: window_sum([M1. Workdays])
4. M4. Average Last 3 months: [M2. Window Sum Sales]/[M3. Window_sum Workdays]
5. D1. Display:
6. Drag the required objects to the indicated locations and filter D1. Display on TRUE
workday nalmai version 10.5.twbx 43.6 KB