From the German language instruction film series (early 1970's) "Guten Tag, Wie Geht's," this episode is entitled "Kennen Sie Meinen Sohn?"

This series of films was award-winning and considered fresh and innovative at the time. Now, however, it is extremely rare and hard to find. Most copies were on 16 mm film, some on the old 3/4 U-Matic video tapes. From the web:


GUTEN TAG WIE GEHT'S: Kennen Sie meinen Sohn?
Library Synopsis
A follow-up series to the 'Guten Tag' series (see BNFC, vol.12), intended for Ge rman language studies and designed as a complete course in intermediate conversa tional German. Twenty-six films, which follow the experiences of four Germans. A 302 page text book, a reader and an illustrated workbook are also available. Also available for videocassette.

I have about 18 of these. If there is interest, I can post more.

Also from the web:

‘Kennen Sie meinen Sohn?’ (‘Do you know my son?’, Guten Tag wie geht's #1 ) (1966) 15m, dir. Rudiger Graf. The ‘Guten Tag wie geht’s’ series, filmed a year following the former series, differs from its counterpart in several respects: the story lines are more involved, the series is filmed in color, and credits are always given to film personnel. Graf’s film is significant in view of its treatment of cross-generational relationships. Here, music professor Hoffman’s son has been away at college for awhile. Upon hearing his son now has long hair and a beard, he visits the university in search of his son’s residence. Hoffman quickly finds himself immersed in 1966 Munich counterculture, and engages in drinking and revelry at a psychedelic "hippie bar". The staid-looking professor eventually finds himself with a five-o’clock shadow, a new group of friends, and a reaffirmation that outward appearances have little to do with the person inside. A bit tipsy, he then relates this philosophy to his son who has just arrived, newly-shaved and barbered, and shocked at his father’s appearance.
Bearing in mind that the episode was filmed in 1966, no educational film made in North America up to that time, to my knowledge, had ever embraced these inter-generational commonalties existing in spite of differing external appearances. Nor did they realistically address the beneficial social aspects of the drinking of alcoholic beverages, which generations of Europeans had successfully integrated into family meals and get-togethers. Hippies, responsible social drinking, and long hair were clearly avoided in educational films originating in the western hemisphere.