this.authService.tokenObs.pipe( map(res => res),mergeMap( token =>
    this.service.getUsers(token).subscribe(res2=>{
            console.log('res2', res2)
  })
));

this.authService.tokenObs.pipe(
     map(res => res),
     mergeMap(this.service.getUsers(token))
).subscribe(res2=>{
    console.log('res2', res2)
});