A change can have Problem Items, Impacted Items and Solution Items.
Any Item can be in Problem report, change request and change notice.
How can I define in the stylsheet of an IR all the changes this IR is in.
It is possible to do this in Impact Analyses, but this overview gives to much information most of the time and is confusing for the users.
A bit of customization would be required to display all change objects IR is part off on the IR stylesheet.
 In BMIDE create a runtime attribute of type 'TypedReference' (on ItemRevision) to ChangeItemRevision object. Set array as unlimited.
 Develop the getter method for this property to retrieve Change objects (GRM call to get primary objects) using the appropriate change relation (impacted item relation or Solution Item relation)
On the Item Revision stylesheet (say summary sheet), you can set up an 'Objectset' (tableDisplay, or treeDisplay or listDisplay) with source as: <property name from step 1 above>.ItemRevision.
The above steps will help you display change objects related to an IR with 'CM Impacted Item' relation.
You could improvise the above steps or use the same approach (and create additional runtime attribute) for 'CM solution item' scenario.