You can limit the replan to a WBS element and its children using the Limit to WBS Leg option. The option is available for all replans except Set Estimate to Complete = Baseline.
To select a WBS leg, complete the following steps:
After selecting a replan option, click the Browse button in the Limit to WBS Leg group box. MPM displays the Limit to WBS Leg dialog box.
Expand and collapse the legs by clicking the Expand/Collapse buttons. If you select a collapsed parent element, the parent element and its children will be included in the replan. If you select a child element, only that child element will be included in the replan.