Use the Drop Dimension to Graphics command, available from the Dimension shortcut menu, to convert a dimension into individual elements such as lines and text boxes.
From the active drawing sheet, place drawing elements and then place a dimension. For more information on using dimension commands, see Dimensioning Drawing Elements.
Right-click the dimension to open the Dimension shortcut menu.
Select Drop Dimension to Graphics.
The dimension is converted into a group of elements.
With the group selected, click Ungroup from the Change toolbar.
You can now select each individual element.
In the figure below, a dimension has been placed for one side of a rectangle.
After the dimension is converted and ungrouped, each element, such as the text box, can be selected.