Extract words from String Column

[#1]

How do I create an Output1 column to extract all the words starting with "_D" from a column called String1? 

String1                                      Output1

PRD_D30405_v1                     D30405

PRD_MH1_D4375                   D4375

FET-D3245_v2_D43453          D43453

BDT_33tr-ge_DT3746_v2       DT3746

[#2]

Here is the formula that I used to get your result

Word( 1, Substr( :String1, Contains( :String1, "_D" ) + 1 ), "_" )

[#3]

You can also use Regex. This should work with your examples

Regex(:String1, "_(D[A-Z0-9]+)", "\1");