As hodgey said the TBS and DNR functions don't/can't do anything while recording (in Camera mode). They are only available during playback (in Player or VTR mode depending on your model of camcorder). If you record the video on the Hi8 camcorder and then play it back on the D8 camcorder, the D8 may have the TBC and DNR functions available during playback. Some D8 camcorders cannot playback Hi8 tapes at all. I don't know if all that can playback Hi8 also have the TBC/DNR function though it seems likely that they would.
Also, on a D8 camcorder that can playback Hi8 tapes, the TBC/DNR functions are ONLY available when playing analog (Hi8 or Video8) tapes. Since a D8 recording is already digital (DV format) they could not serve their purpose of aligning and cleaning up the analog signal (since there isn't one).
Here is a discussion of Camcorder models recommended for Video8 and Hi8 playback for digitizing.
Note: Sony has most of their manuals available online.
Here is the relevant info from the CCD-TRV 67/87 manual: