Union ranges
The option creates a single range that includes the cells of two or more ranges. For example the union of A1:D1,A3:D3 is A1:D3.
This feature can be useful if the two ranges are separated by a hyperblock, for example, and all the values displayed in the hyperblock must be refreshed.
In View mode, a hyperblock displays a list of elements. The hyperblock expands and contracts according to the number of elements in the list. But typically, in Design mode, a hyperblock occupies cells on only a single row or column. Any formulas and actions that you specify in the hyperblock are copied to every element in the list on which the hyperblock is based. But executing an action on one element does not affect the other elements. Thus, specifying the option in an action only refreshes the element on which the action is executed. This is an issue if every element displayed by the hyperblock must be refreshed.
The solution is to specify a range of cells above the hyperblock and a range below. Then use the Union ranges option to specify that all cells between the two ranges are refreshed.