I am probably descended from Hans Bruegger and Elsbeth Bueschlen of Frutigen, Canton Bern, Switzerland. He was born in 1583, she in 1585, and they were married in 1606. Note that "Bueschlen" and "Buschlen" are the same names; the original spelling has the letter "u" with an umlaut (two dots) above it.
I have not followed the Bueschlen line further back in time, but here are sources of information (the last is a microfilm available through your local LDS Family History Center) which appear to deal to some extent with the Bueschlen family in Switzerland:
"The history of the Rosti family in Switzerland and America, 1555-1991 : allied lines: Wafler, Buschlen, & Grossen", by Marilyn Roesti
"Stammbaum Weibel Niklaus Büschlen, Adelboden : Büschlen - Dänzer - Maurer, mit Linien Lauber und Schranz und den vielen Abzweigungen", by Gilgian Maurer
"Stammbaum des Geschlechtes Büschlen, Adelboden und Frutigen" (Genealogy of the Büschlen family of Adelboden and Frutigen, Switzerland. Descendants of Bartlomes Büschlen of Rinderwald) FHL INTL Film 1183692 Item 8
Unfortunately, the parish records of Frutigen have not yet been microfilmed by the Latter Day Saints, so one has to use the services of a town genealogist there to do research on one's family (I had to do this) unless you can read German and can make the trip there yourself. I have the name and address of the individual who did the research for me, if anyone is interested; she did three hours worth of research and charged twenty-five dollars an hour.