In Siemens nx mirror feature command use to copy a feature and mirror it across a plane.
Where do i find it?
From menu: Insert -> associative copy -> mirror feature.
From home tab: Feature group -> More gallery -> associative copy gallery -> mirror feature.
How to use mirror feature command?
1. Select insert -> associative copy -> mirror feature.
2. In the mirror feature dialog, in the features to mirror , select feature is active. In the window graphics, select features to mirror.
3. In the mirror plane group, plane list you can select existing plane or new plane. In this example, i will select new plan, specify plan is active. Select plane (face)
4. in the preview group, left click show result to see result.
5. Click OK or apply to complete.