Stephen Jones, Danny Wilson and Matt Sherratt will help coach Wales on next summer's Pacific Islands tour.
Robin McBryde will act as head coach with Warren Gatland and Rob Howley touring New Zealand with the British and Irish Lions.
Scarlets backs coach Jones and Cardiff duo Wilson and Sherratt will complete Wales' backroom staff for the Tests against Tonga and Samoa.
"This is an important announcement that provides an opportunity to give three senior regional coaches the chance to work in the international coaching environment, with a view to us both learning from them and adding to the personal development of each individual," WRU chief executive Martyn Phillips said.
"We have a clear strategy in Welsh Rugby, with coaching and coach development a central priority at all levels of the game.
"It will be of tangible benefit to Welsh Rugby in the long term that, within a small window during their coaching careers, we are able to provide significant development opportunities to Danny, Matt and Stephen mirroring the opportunities given to Warren, Rob [with the British and Irish Lions] and Robin [as head coach].
"The intention is also that these appointments will further unite the key professional coaches in Wales, leading to even better relationships and sharing and alignment of coaching philosophy. We see this as the start of a push to work closely with the regional coaches and very much intend to involve additional coaches in the years ahead as opportunities arise."
Wilson led Wales Under-20s to a second-place finish at the 2013 Junior World Championships, leading to stints at Bristol and now Cardiff.
Cardiff attack coach Sherratt joined Wales' backroom staff for the November series, with head coach Gatland on his sabbatical to build up to the Lions tour next summer.
Former fly-half Jones won 104 caps and two Six Nations Grand Slams for Wales, and has impressed in coaching roles at both Wasps and now Scarlets.
"We are delighted announce that Danny, Matt and Stephen will be joining the set-up for next summer's tour," said McBryde.
"The appointments will not only be hugely beneficial to the national squad, but to the whole game in Wales providing an opportunity for all three coaches to further enhance their coaching experience.
"Next summer we are going to be facing two passionate rugby nations, it will be a challenge for both players and coaches, but also an opportunity for us all."