Use billDecompositionCoreByName instead of decompositionCoreByName in VariableReferredParameters

src/lib/components/variables/VariableReferredParameters.svelte

@@ -156,7 +156,7 @@
   {#if billDecomposition?.children !== undefined}
     <div class="flex flex-col">
       {#each billDecomposition?.children as { name }}
-        {@const decomposition = decompositionCoreByName[name]}
+        {@const decomposition = billDecompositionCoreByName[name]}
         {#if !decomposition.hidden}
           <a
             class="flex justify-between items-center px-4 py-2 tracking-wider hover:bg-neutral-100 active:bg-neutral-200 font-medium text-gray-700"