To Align Dimensions
1. Select the dimension to which you want to align other dimensions. The dimension is highlighted.
2. Press CTRL and select the remaining dimensions individually. Alternatively, you can use region selection to select the remaining dimensions. Region selection can cause non-dimension objects also to be selected. However, the alignment only applies to the selected dimensions. The selected dimensions are highlighted.
3. Right-click and click Align Dimensions on the shortcut menu to align the dimensions in the X- or Y-direction. The dimensions align to a single plane perpendicular to all the witness lines of the selected dimensions. The position of the first selected dimension determines the plane to which the dimensions align and the orientation of the witness lines.
Alternatively, click Move Dims to Plane to align the dimensions in the Z-direction. Creo Parametric moves the dimensions to the annotation plane of the first selected dimension. Z-direction extension lines are added to the model for dimensions that are moved out of their original placement plane.  
You can also align a dimension with another dimension by dragging it near the other dimension. When the arrows of the dimension are in proximity they snap to each other.
To realign a group of dimensions, select a dimension and move it. Next, select all the dimensions to be aligned and align them.
You can move each dimension independently to a new location. However, aligned dimensions do not maintain their alignment if you move one of the dimensions.