ServiceNow Discovery : derive information for a custom field based on discovered data

[karabasappak]

Hello,

We have custom field in CMDB, say 'Custom_field'.

We are using cloud discovery, we want to map value for 'Custom_field' based on the tag values associated with cloud subscription. Please suggest if there is a way to

-- Run script on discovered data before its pushed into CMDB

-- Read tag values from discovered data

-- Based on the tag values, add value for 'Custom_field'

-- Value for 'Custom_field' should be pushed into CMDB along with discovered information

[Casey F]

If I'm understanding the ask correctly, an approach would be a few steps:

Step 1: Discovery Pattern Pre/Post Scripts
Edit or create a new pattern with pre-scripts and post-scripts to collect this tag data from the pattern and map to the appropriate custom CI field. 

Community post link diving into this some: LINK 

Step 2a: (if using Discovery) Create/Modify Identification and Reconciliation rules 
Find or create the appropriate reconciliation rule and related maps for the custom field

Step 2b: (If using import sets) Update Transform maps to map this variable/field from the pattern/script to your CI field

Without having run into this personally, and no means to test quickly - I think this would be the ideal approach and hope it helps guide you into the solution!