What about that?

Select Titles
Map:
item()['Title']
Unique Titles
Inputs:
union(body('Select_Titles'), body('Select_Titles'))

Loop input:
outputs('Unique_Titles')
Filter array
From:
variables('List')
Filter expression:
item()['Title'] is equal to items('foreach_Title')
Collect the result with a compose action outside of the loop:

Inputs:
body('Filter_array')
This is the result, an array of arrays grouping the records by Title:
[
[
{
"ID": 1,
"Title": "A"
},
{
"ID": 2,
"Title": "A"
},
{
"ID": 5,
"Title": "A"
}
],
[
{
"ID": 3,
"Title": "B"
}
],
[
{
"ID": 4,
"Title": "C"
}
]
]