To list all aliases and their functions:

Get-Alias

To get all aliases for specific cmdlet:

PS C:\\> get-alias -Definition Get-ChildItem

CommandType     Name                                               Version    Source
-----------     ----                                               -------    ------
Alias           dir -> Get-ChildItem
Alias           gci -> Get-ChildItem
Alias           ls -> Get-ChildItem

To find aliases by matching:

PS C:\\> get-alias -Name p*

CommandType     Name                                               Version    Source
-----------     ----                                               -------    ------
Alias           popd -> Pop-Location
Alias           proc -> Get-Process
Alias           ps -> Get-Process
Alias           pushd -> Push-Location
Alias           pwd -> Get-Location