Either of these examples will work:
# without splatting
$getprocess = "notepad","onenote"
Get-Process -Name $getprocess
# using splatting
$getprocess = @{processname="notepad"}, @{processname="onenote"}
ForEach ($p in $getprocess){
get-process @p
}
But unless you're going to provide more than one parameter inside each hash using splatting in this case is more work than it's worth. A simple list of process names is sufficient.
Here's an example of using splatting to provide a different set of parameters for each process:
$getprocess = @{processname="notepad";includeusername=$true}, @{processname="onenote";fileversioninfo=$true}
ForEach ($p in $getprocess){
get-process @p
}