Unity property attribute to conditionally enable a property in the inspector.

ConditionalEnableAttribute.cs

using System;
using UnityEngine;

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Field | AttributeTargets.Property | AttributeTargets.Struct)]
public class ConditionalEnableAttribute : PropertyAttribute
{
    public readonly string ConditionalPropertyName;

    public ConditionalEnableAttribute(string conditionalPropertyName)
    {
        ConditionalPropertyName = conditionalPropertyName;
    }
}

ConditionalEnablePropertyDrawer.cs

using UnityEditor;
using UnityEngine;

[CustomPropertyDrawer(typeof(ConditionalEnableAttribute))]
public class ConditionalEnablePropertyDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        var conditionalDisableAttribute = (ConditionalEnableAttribute)attribute;
        var isEnabled = IsEnabled(conditionalDisableAttribute, property);

        using (new EditorGUI.DisabledScope(!isEnabled))
        {
            EditorGUI.PropertyField(position, property, label, true);
        }
    }

    static bool IsEnabled(ConditionalEnableAttribute conditionalEnableAttribute, SerializedProperty property)
    {
        var conditionalPropertyPath = property.propertyPath.Replace(property.name, conditionalEnableAttribute.ConditionalPropertyName);
        var conditionalProperty = property.serializedObject.FindProperty(conditionalPropertyPath);

        if (conditionalProperty == null)
        {
            Debug.LogWarning($"No conditional property found for ConditionalEnableAttribute: {conditionalEnableAttribute.ConditionalPropertyName}");
            return true;
        }

        return conditionalProperty.boolValue;
    }
}