With Omniscope, fields are used throughout the application in many different places - as filters within different pages, as measures or breakdowns within views, etc. As such it isn't possible to summarise where a field is "used" elsewhere within the file (unlike Excel, which simply has sheets of grids of cells).

However, in the forthcoming version 2.5, field tooltips (seen when hovering over field headers in the table view) summarise the direct references to/from the field in all formulas. I suspect this is the closest to what you are asking for.