Thanks for the formulas. They work. What if the input text already contains data (e.g., Tuesday & Wednesday), and I want the text input to display the parent.default data? In other words, when the text input has data from SharePoint, it will display that data. However, when a user clicks on either of the checkboxes, the original data will need to disappear, and the checkbox data will be displayed.
I tried the following formulas, but is not working
If(Checkbox.Value=false || Checkbox2.Value=false || Checkbox3.Value=false || Checkbox4.Value=false || Checkbox5.Value=false,Parent.Default,Concat(Filter(Table({SelectedDay:If(Checkbox,"Mon")},{SelectedDay:If(Checkbox2,"Tue")},{SelectedDay:If(Checkbox3,"Wed")},{SelectedDay:If(Checkbox4,"Thur")},{SelectedDay:If(Checkbox5,"Fri")}),SelectedDay<>Blank()),SelectedDay," & "))