Hi,

We have recently added support for variables in DataManager. You cannot edit the variables in the functions dialog box. Instead, in the Field organiser, click the "Tools" button at the bottom of the block and select "Edit variables...". Any variables that you create here can be used in any formula that you create in this or subsequent blocks. If you want the variables to be available in any downstream blocks then you need to select "Preserve formulas/variables" in the tools dropdown.