Interface Value

HI, You would need to save 2nd rule input value in first text field's saveInto parameter like below,

a!textField(
label: "Training Event",
labelPosition: "ABOVE",
value: ri!record.trainingevent,         <<<<<<<<<<<<<<<<<<<<<<
saveInto: {
ri!record.trainingevent,
a!save(ri!equipment.trainingEvent,ri!record.trainingevent)
},
characterLimit: 255,
showCharacterCount: false,
required: false
),

Here is text field #2:

a!textField(
label: "Training Event",
labelPosition: "ABOVE",
value: ri!equipment.trainingEvent,         <<<<<<<<<<<<<<<<<<<<<<<<
saveInto: ri!equipment.trainingEvent,
characterLimit: 255,
showCharacterCount: false,
required: false
),

Gopalk's solution is probably the correct one for your use case, but it will help if you understand a bit more about what's happening here.

In Appian, for any user input field, the "saveInto" parameter only has any effect whatsoever when the user directly interacts with that field.  What you've done here, on the other hand, will cause the "field #2" value to always show the value of ri!record.trainingevent, and if any changes are made to it from that field, only then will the changes save only to "ri!equipment.trainingEvent", but those changes will not be reflected in the field itself since its value is set to only reflect ri!record.trainingEvent.

Instead, per the code GoalK posted already, we have the first "training event" field save any user input directly into both data targets simultaneously.  Then the "field #2" value is changed to correctly reflect its own value, and any changes to that field will change only its value.  This will roughly accomplish the behavior you're after. 

The one thing to be careful of here, though, is that if the user enters a value in Field 1, then makes an edit to Field 2's value, but then also goes back and edits Field 1 again, the new value for Field 1 will overwrite the Field 2 data without caring that it already has a value.  If this is your intent, then that's fine, but if there's a chance this will cause further user confusion, then you will need to refine the Field1 saveInto to avoid overwriting Field 2's value if it's anything other than "blank".