To Add or Modify Anchors

In the Project Setup dialog box, expand Isometric DWG Settings. Click Dimensions.
On the Dimensions pane, in the Iso Theme list, select the iso theme for which you want to modify the dimension styles to different dimension types.
From any tab (Under End to End (Overall), String, or Locating), under Anchors box, click Add.
In the Piping Component Selection dialog box, Standard tab, do the following:
- Specify one or more components as anchors to dimension.
- Specify one or more end types to components as anchors to dimension.
- Specify one or more additional conditions to components as anchors to dimension.
Click Advanced tab and enable the Use filter to specify anchor option to select any existing filter as anchors to dimension. Click Add Dimension Anchor.
On the Dimensions pane, from any tab (Under End to End (Overall), String, or Locating), select any anchor.
In the How to Dimension drop-down list, choose a dimension method.
From any tab (Under End to End (Overall), String, or Locating), select any anchor and click Delete Anchor Point to delete the selected anchor.