LOD or a Filter to Return the Amount with Min Date

Morning all,

I need a hand making this calculation and I am open to ideas.  I am using 2018.1

Here is my issue:  Do to some bad design and logic I have parent and child records in my table but I have no other column that will help me to "filter" out the child records.  The result of this is values that are doubling but it only happens in one area.

This is what my underlying table looks like:

As you can see each transaction has a type.  Types could be Travel, Supplies, Overtime, etc.  In my case, the issue is with Travel.

Now I have highlighted the same table to break out the parent record from the child record:

This is the logic that I need and cannot seem to come up with:

Condition 1: For Transaction Type = Travel Records

Condition 2: Where the Travel Order Number >1

Then return the Amount equal to the MIN(Transaction Date)

If all those conditions are met then this is what I should see:

Now what I have been trying to do is this:

Attempt 1:

IF ATTR([Transaction Type])='Travel' AND COUNT([Travel Order Number])>1 AND ATTR([Transaction Date])=MIN([Transaction Date]) THEN SUM([Amount])

ELSE SUM([Amount])  //This is for records that are not travel.

END

Attempt 2:

{FIXED [Travel Order Number],[Transaction Date]:SUM(IF COUNT([Travel Order Number]>1 AND [Transaction Date]=MIN([Transaction Date]) THEN [Amount])}

I think the LOD approach might be best but I cannot figure out how to get the IF THEN logic inside the LOD Expression.

Thank you,

Scott