The normal rule of thumb for posing a figure is to implement x and z translations in the BODY actor, and y translations in the hip actor. If you always follow this scheme for posing your figure, and don't use the new P7 feature of saving pose data for the BODY actor, then poses you save will not cause the figure to jump to different locations. Although this takes care of poses you make, it does not help if you need to use a pose that was made by someone else who did not follow this scheme.

Attached above is the text of a pose file that may (or may not) help. Applying the file will force the hip to adopt a translation of zero (no translation), and It will prevent a normal pose file from translating the figure when it is applied. When I say a "normal" pose file, I mean one that does not contain translation data for the BODY actor. Most pose files don't contain data for the BODY actor, but P7 introduced to possibility to save BODY data in a pose file.

Once you apply the "NoHipTran" pose, pose files will not be able to translate the hip, and neither will you. Thus the only way to change the translation of the figure will be to translate its BODY actor. Rotations of the hip will not be affected.

There is a way to unlock the hip translations. In the BODY actor you will find 3 new dials, HipXT, HipYT, and HipZT. Setting all 3 of these dials to a value of "1.0" will restore the hip to normal operation. Because the hight of a figure is normally controlled by yTran in the hip, you may find poses work better if you set the HipYT dial to a value of 1.0. I did not set this as the default because you asked for a way to "keep the same x-y-z positioning". You may find that with the hip translations restrained you will get undesirable consequences if IK is used on the figure. The attached file requires P6 or above.