Your question isn't totally clear...
1 part means it's always up to you how much you want to make. Make just what you think you will need for your recipe, whether that's 1 spoon of each oil or 1 cup each. Don't make more than what you need.
In general, you're going to use the same amount of all five of the oils. But you'd need to post the recipe word for word for me to be sure.
A suitable substitute for evaporated milk in a recipe is to mix equal parts of whole milk and half-and-half to achieve a similar consistency and flavor.
The term "equal parts" refers to dividing something into portions that are the same size or quantity. It is often used in cooking, mixing, or measuring, indicating that ingredients or components should be combined in equal amounts. For example, if a recipe calls for equal parts of water and vinegar, it means to use the same volume of each ingredient.
You have half as much A as required by the recipe.
A good substitute for ssamjang in a Korean recipe is a mixture of equal parts gochujang and doenjang.
A suitable substitute for mascarpone in a recipe is a mixture of equal parts cream cheese and heavy cream.
A good substitute for Marsala in a recipe is a mixture of equal parts of sweet sherry and a dry white wine.
A suitable substitute for Aleppo pepper in a recipe is a combination of equal parts paprika and cayenne pepper.
You can substitute cream cheese or a mixture of equal parts of Greek yogurt and heavy cream for mascarpone cheese in a recipe.
You can substitute turmeric, cumin, coriander, and ginger in equal parts for yellow curry powder in your recipe.
A good substitute for pineapple juice in a recipe is a combination of equal parts of orange juice and lemon juice.
A suitable substitute for blackstrap molasses in a recipe is a combination of equal parts dark corn syrup and maple syrup.
Try a mixture of equal parts of water and regular white glue :)