$ echo "[extensions]" >> $HGRCPATH
  $ echo "schemes=" >> $HGRCPATH
  $ echo "remotenames=" >> $HGRCPATH

  $ cat >> $HGRCPATH <<EOF
  > [schemes]
  > dotdot = ../{1}
  > EOF
  $ FILTERPWD="sed s%`pwd`/%%g"

  $ mkcommit()
  > {
  >   echo $1 > $1
  >   hg add $1
  >   hg ci -m "add $1"
  > }

  $ hg init alpha
  $ cd alpha
  $ mkcommit a
  $ mkcommit b
  $ hg branch stable
  marked working directory as branch stable
  (branches are permanent and global, did you want a bookmark?)
  $ mkcommit c
  $ cd ..
  $ hg clone alpha beta | $FILTERPWD
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd beta
  $ mkcommit d
  $ hg co -C stable
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'merged'
  $ cd ..
  $ hg init gamma
  $ cd gamma

  $ cat > .hg/hgrc <<EOF
  > [paths]
  > default = ../alpha
  > alpha = ../alpha
  > beta = dotdot://beta/
  > EOF

  $ hg pull | $FILTERPWD
  pulling from alpha
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files
  new changesets 1f0dee641bb7:95cb4ab9fe1d
  (run 'hg update' to get a working copy)
  $ hg pull beta | $FILTERPWD
  pulling from dotdot://beta/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  new changesets 78f83396d79e:8948da77173b
  (run 'hg update' to get a working copy)
  $ hg co -C default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch default
  marked working directory as branch default
  $ mkcommit e
  $ hg merge stable
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'merging stable'
graph shows tags for the branch heads of each path
  $ hg log --graph
  @    changeset:   6:ce61ec32ee23
  |\   tag:         tip
  | |  parent:      5:6d6442577283
  | |  parent:      4:8948da77173b
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     merging stable
  | |
  | o  changeset:   5:6d6442577283
  | |  parent:      3:78f83396d79e
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     add e
  | |
  o |  changeset:   4:8948da77173b
  |\|  branch:      stable
  | |  branch:      beta/stable
  | |  parent:      2:95cb4ab9fe1d
  | |  parent:      3:78f83396d79e
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     merged
  | |
  | o  changeset:   3:78f83396d79e
  | |  branch:      beta/default
  | |  parent:      1:7c3bad9141dc
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     add d
  | |
  o |  changeset:   2:95cb4ab9fe1d
  |/   branch:      stable
  |    branch:      alpha/stable
  |    user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     add c
  |
  o  changeset:   1:7c3bad9141dc
  |  branch:      alpha/default
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     add b
  |
  o  changeset:   0:1f0dee641bb7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     add a