Sort of. Steve Miller and Boz Scaggs were both original members of the Haight-Ashbury mid-late 60's S.F. "counter-culture" jam-rock, pop bands like the Jefferson Airplane, Grateful Dead, Quicksilver Messenger Service, and lastly, Santana. I think Scaggs played rhythm or co-lead guitar in the Steve Miller Band up until his major breakthrough, 1973's The Joker. IIRC, Scaggs left for an eventually very successful solo career after the Joker's release because it wasnt until 3 years after that album's release that Steve Miller Band released a follow-up, 1976's Book of Dreams.
Despite being of the most critically and commercially successful bands of the 1970's and early 80's, Steve Miller still strikes me as one of rock's most underrated, somewhat over-looked acts and musicians over the past 50 years. He could jam with the best of them even if his band became more well-known for their many radio-friendly hits in the 70's and early 80's. Songs like "Living in the USA", " Space Cowboy", "Gangster of Love"--they were good, well-written tunes in his pre-Joker days. He was also a very sharp, highly intelligent businessman in that he held out for a huge signing bonus and a then-high royalty rate. He was one of a few rockers who helped eventually change the economics of rock music where it became more artist-friendly.